To All,

Once again posed with another issue.

I thought I posted about a similar issue a while back but I can’t find it.

The issue is vehicle not starting within 1 or 2 seconds..

What used to take 1 or 2 revolutions now is taking +10 or more.....Just all of an sudden!!!

History
1. Replaced fuel pump with original Denso Unit. Also replaced the filter and pressure regulator. This was several weeks ago.....No Issues!!!!
2. Lost CC and while investigating Fuses must have banged into fuel pump interrupter Cutout switch mounted on passenger door pillar. Reset unit....... no further issues.
3. Working on hood today 9/23 went to move car and it just turned over a bunch of times, finally starting.

This also happened prior to replacing the fuel pump. What I noticed was that the filter attached to the bottom of the original fuel Pump was completely blocked except for a hole that was in the filter. My guess was that the filter was plugging up making it difficult to start.....Once it blew(sucked) a hole in the filter it got easier to start.

Once pump changed..... NO MORE ISSUES....UNTIL NOW!!!!

Possible causes....FUEL OR SPARK??????

1. If an injector were plugged or partially blocked could this cause the Change to immediate ignition (1 or 2 revs) condition Of the engine?
2. If a coil was going bad....Is it either good or bad....Is it possible going bad makes it more difficult to start?
3. Crank position.....Does it either work or fail?
4. Can’t imagine any fuses cause this kind of an issue???
5. Spark Plugs??

After it starts (+10 cranks), it runs fine....... no issues, misses hesitations etc.

Thanks for your responses

Softball60/Paul

 

Paul,

A couple of thoughts:

- Does it make any difference if you turn on the ignition and wait until the fuel circuit is completely primed before engaging the starter? This might indicate that its dropping fuel pressure at rest and needing to fully reprime the fuel rail.

- The Engine Position Sensor )Sometimes referred to as the Camshaft Position Sensor) could be failing. All this does is tell the ecu if the engine is on the firing or exhaust stroke. It does nothing once the engine has caught. If it has failed, the engine has to turn more times until it "works out" when it is on the firing stroke.

Good luck

Paul

 

Thanks PTA’s,

Before I try to start the engine I let the fuel pump do its thin g ...and it is I can hear it.

I was thinking engine position sensor but what do I know.

I’ll give it a day or two and check again?

Is it difficult to install the sensor...I heard it was easy after you have done it before!!!!

Where is the sensor located....Is is on the fron t of the engine on top of the crankshaft?


Thanks

Softball60?paul

 

Does this problem get worse on hot starts? Or any temperature impact?

 

VancouverXJ6,

I do not believe it is any different.

What were you thinking?

Softball60/Paul

 

Crank sensors if temp is an issue. My car when first bought had issues as air temp vs hot start would move the weak sensor just abit causing problems. Metal does expand snd contract alot.

I would check your fuel pressure regulators, and delete the useless one if you have two. My car currently needs to prime twice to fire on with somewhat lackluster starting...its odd to like your issue some days its a light switch other times its an embarassment as it chugs and struggles to life.

A firm SLAM to the gas pedal helps. How are your fuel filters? Swirl tank? Etc

 

Assuming an AJ16 6cyk engine, you havent said?

The Cam Angle Sensor, already mentioned, may simply be out of time.
Quite common, and matches the symptoms you are describing.

Failure is rare, but not unknown.

The plug in the side of that unit does get grubby, so unplug it, clean the socket and plug well, it may be that simple.
I also suggest cleaning the plug and socket of the Crank Angle Sensor, they are well dooumented as filling with crud.

Retiming that thing is NOT hard, and I have a PDF somewhere on doing that. I will go looking later when I finish with the S Type.

Just so we on the same page, the Cam Angle Sensor is the round whizzy thing on the front SIDE of the engine, where a distributor once lived on earlier versions.
The Crank Angle Sensor, ismounnted on a bracket off the timing cover.

 

Here you go.
Too wet and cold outside, the S Type can wait.

FORGOT, it happens.

That write up is based on my X300. I have NO idea the layout on a 1996 AJ16 XJS, probably the same. You will need access to the front crankshaft bolt hex, AND a visual of the toothed wheel. Once that fans were out of the way, more than enough room for any task on the front of that engine.

 

To all who have responded,

Thank you

I have purchased a crank sensor and will attack that first.

As I mentioned earlier after the long crank and the engine fires up....It runs and drives like normal. I am a little Leary of trying to retime the engine.... but if it comes to that I will figure it out based on Grants’ information.

Softball60/Paul

 

Curiosity got the best of me....so I started look at what Grant was referencing.


Grant
1. Should I assume that when I match up the missing crank tooth with the Crank Sensor metal tip.....This should either be TOP DEAD CENTER or 180 degrees out so that’s why you rotate one (1) more time.
2. Once at TDC and looking at the Cam Sensor.....There should be a mark either within the bubble or, if off..... slightly outside the bubble...and that requires resetting as described in the attachment supplied.

Do I have it correct?

I am just waiting for the new crank sensor.

I will have to pull the fan blade off, the fan shroud off to get to the crank sensor.

Softball60/Paul

 

Paul,

100%, have a BEER mate.

My X300 was just outside that window and there was enough slot to line it up, now the damn thing starts on 1st rotation of the starter motor, not the 1st rotation of the engine, its that quick.
The X300R, was WAY out, and I had to lift that Sensor to drop it in a few teeth around, now that is the same, scary quick.

Fan Blades, BUGGA, they still had them in the 2 door beasts, BUGGA again.

 

Can't help thinking that an obvious is being overlooked ...

And condemned the injectors to death ... and potentially the pump

If you saw how much crud I've removed not only from my fuel lines but from the injectors themselves from an engine that still ran you'd be surprised - and my engine did run with seemingly few issues, although it is a V12 it too took plenty of turns to get it going.

The tendency I see in many is to go charging off into the complex without inspecting the basics first. Fuel pressure may be fine (or may not) but still take time to get through clogged injectors, flow rate also matters or you're probably running lean - although I know you have a closed loop system (lambda) it doesn't mean flow is OK - the injector duration may be much longer to maintain the magic numbers. If the fuel pump filter is clogged then it is clogged by crud, that crud now bypassed the filter and is everywhere else. I had a Jetronic fuel system in a VW Scirocco GTII destroyed by corrosion from a failed filler pipe - and it was hard to start but start it did

 

Here is what I experienced today. Hard starting, esp when shut down after a run.

My evap emission system was clooged, resulting in a huge vacuum in the fuel tank. I removed the rubber seal from the cap. Runs like a different engine

 

Thanks for the responses. Here are a couple things of note and or questions

Grant

1. Regarding the idea of getting things to top dead center and the cam side. You mention to loosen the two (2) screws holding down the plate and lifting it up to adjust the cam sensor if is not in the bubble.
A). When lifting up the plate to reposition the gear.....HOW HIGH AM I LIFTING THE PLATE?
B.). Am I holding up the plate and moving the sensor at the same time?
C.). Is all of this being done static?.....Engine not running!!!


Ben

1. I discussed in the being of this thread
A.). Replaced the fuel pump, in line filter and pressure regulator. This was ~ 3 weeks earlier
B.). The tank was extremely clean. The fuel pump was the original pump with 108K mile.....That’s probably why the filter on the fuel pump was plugged.
C.). As I mentioned even now with the difficult starting situation it runs and drives like new.
D.). The injectors have ~5K miles on them. If what I am thinking is now the issue, I will look at the injectors. I use additive all the time to clean the injectors

Scott

No issues with the vacuum system. I had checked the fuel cap pressure

Guys thank you all for the responses.

Waiting for the crank Sensor ...Should be tomorrow....Will let you know the results.

Softball60/Paul

 

Just based on the filter being blown out, if it was clean and you're sure. My injector filter baskets were choked with rust - just serviced and cleaned all mine - two out of twelve are bad and they've only 57k miles on them, the spray patterns on all of them aren't much good but I put this down to the technology of the day and low operating pressure.

 

When was the last time the fuel filter was changed.
After all the stuff fuel related you have done has probably knocked crud loose.
No matter when you changed it, change it again.
I don't mean the strainer at the bottom of the pump.
The fuel filter is under the left front wheel well.
It wouldn't hurt to run the pump a few minutes into a clean rag to see what's what.

 

Equiprx,

Thanks for the suggestion but.......The filter is a couple of weeks old.

When I installed the new pump as mentioned I replaced, fuel pump, in line filter and fuel pressure regulator.

When installing the pump the tank looked brand new on the inside, nothing on the walls or on the bottom.

rubber looked good.....no issues!

Thanks

Softball60/Paul

 

I gotta stop talking Aussie, things get lost in the assumptions and lingo. Add old age, and we are in strife.

1) Remove the 2 torx screws (small), AND lift off the tin lid. It is simply a cover to keep the shiiit out, eith a viewing window for timing the thing, just like a distributor in any other car.

A) Remove the tin plate lid, and put it to one side. DO NOT lose those screws.
B) With the locking bolt OUT of the under plate (where the slot is) raise the whole unit. I never measured how far, makes zero difference anyway, simply raise it up, the INNER tin plate will rotate as the unit "unmeshes" with the drive gear. Once clear, rotate that tin inner plate in the direction needed to get the mark on its upper face somewhere near where the window is. It may take a few up and down, rotate a SMALL amount, attempts before the planets align. When putting it back "down", it will basically "slide in", you should not have to PUSH it down.
C) Engine OFF, IGN OFF, keys in pocket.

I will go read that Doco later, and maybe I can fine tune the thing for better understanding. Dont hold your breath, I have Jags that need cuddling.

This Sensor is basically a distributor without cap and wires. It has the slotted plate holding it in place, just like a distributor, and setting the position is really simple. Once the missing tooth is aligned on TDC Compression stroke, raising that Sensor, rotating the inner plate/shaft, maybe 2 or 3 times, and refitting the lock bolt, and the tin cover, takes about 20 minutes for the 1st time.

Getting in there and accessing the crankshaft front bolt hex is clearly going to be a PITA for you, due to engine fan. I would LOOK really hard, I reckon, with your tongue in the Left side of the mouth, right side is usually for the V12, you will get a socket on that hex, and be able to rotate that engine.
I got at that bolt on my V12 engines in the early days, before I fitted thermo fans, NOT easy, NOT simple, but persistence got the job done.

 

Grant,

Got it all apart on the crank end. Had to loosen the fan shroud and fan and was able to get to the crank bolt.

1. Rotated the engine till the spot was inside the crank sensor viewing hole.
2. Removed the oil fill cal and the cam lob was pointing up
3. Checked the cam shaft for alignment and it was within the larger diameter circle on the glass and almost within the bubble. DID NOT MAKE ANY ADJUSTMENT TO THE CAMSHAFT
4. PUT IT ALL BACK TOGETHER AND GAVE IT A START..........SAME THING..........LOTS OF REVS BEFORE IT STARTED
5. COULD IT BE THE CAMSHAFT SENSOR??????
6. I FIND IT EXTREMELY DIFFICULT TO BELIEVE IT IS FUEL RELATED??? MAY END UP EATING MY WORDS!!!!

Thank

Softball60/Paul
Replaced the crank sensor.

 

Paul,

A couple of thoughts:

Each time you're starting it up, are you fully running the car right up to temperature and taking it for a drive before finally turning it off? AJ16s really don't like being run just for a minute two before closing down, and often have trouble restarting after a startup and immediate turn off.

Also does it make ANY difference at all if you turn the ignition to prime the fuel, turn off the ignition and turn on to prime again, and then turn off and turn on again to reprime yet again before finally turning to start the engine? This could help to pinpoint whether its fuel or electrics.

Cheers

Paul